The present invention relates to a fuel cell stack, having fuel cells arranged successively in a stacking direction, an inner covering element, which follows the fuel cells in the stacking direction, and an outer covering element, which follows the inner covering element in the stacking direction and holds the inner covering element and the fuel cells together in a braced state, wherein the outer covering element forms at least a first spring element and a second spring element perpendicularly to the stacking direction, wherein each of the spring elements forms an arc profile that is convexly curved in the direction of the inner covering element and the respective arc profile is separately suspended, and wherein the inner covering element for the spring elements forms a respective receptacle, each being concavely curved in the direction of the outer covering element and accommodating the respective concavely curved arc profile.

The present invention relates to a fuel cell stack, having fuel cells arranged successively in a stacking direction, an inner covering element, which follows the fuel cells in the stacking direction, and an outer covering element, which follows the inner covering element in the stacking direction and holds the inner covering element and the fuel cells together in a braced state, wherein the outer covering element forms at least a first spring element and a second spring element perpendicularly to the stacking direction, wherein each of the spring elements forms an arc profile that is convexly curved in the direction of the inner covering element and the respective arc profile is separately suspended, and wherein the inner covering element for the spring elements forms a respective receptacle, each being concavely curved in the direction of the outer covering element and accommodating the respective concavely curved arc profile.

The present invention relates to electrical network comprising an electrical conductor and, a cryogen source configured to hold cryogen, the cryogen source arranged so that, in use, cryogen is provided to the conductor to maintain the conductor in a hyperconductive state.

The present invention relates to electrical network comprising an electrical conductor and, a cryogen source configured to hold cryogen, the cryogen source arranged so that, in use, cryogen is provided to the conductor to maintain the conductor in a hyperconductive state.

An aircraft includes a fuel cell system including a fuel cell powered by hydrogen received from a supply of hydrogen, and a propulsion unit including a conduit through which a flow of air is propelled. A first heat exchanger transfers heat from the fuel cell to a coolant fluid located in a coolant loop, and a second heat exchanger is located in the conduit for heating the air passing through the conduit by transferring heat to the air from the coolant fluid via the second heat exchanger. This configuration serves to cool the fuel cell while increasing the efficiency of the propulsion unit.

An aircraft includes a fuel cell system including a fuel cell powered by hydrogen received from a supply of hydrogen, and a propulsion unit including a conduit through which a flow of air is propelled. A first heat exchanger transfers heat from the fuel cell to a coolant fluid located in a coolant loop, and a second heat exchanger is located in the conduit for heating the air passing through the conduit by transferring heat to the air from the coolant fluid via the second heat exchanger. This configuration serves to cool the fuel cell while increasing the efficiency of the propulsion unit.

An energy recovery system and method for an aircraft having propellers. Specifically, the system and a method recover energy during the descent phase by setting the aircraft engines in propulsive mode or in windmill mode as needed. In windmill mode, the wind drives the propellers to generate electrical energy which may be stored. A pitch angle of the blade of the propellers may be changed.

An energy recovery system and method for an aircraft having propellers. Specifically, the system and a method recover energy during the descent phase by setting the aircraft engines in propulsive mode or in windmill mode as needed. In windmill mode, the wind drives the propellers to generate electrical energy which may be stored. A pitch angle of the blade of the propellers may be changed.

The present invention relates to a propulsion system for providing controllable propulsion comprising: a fuel cell arrangement (210) for generating electrical energy; a gas generator (250) comprising a compressor (256), a combustor (254) and a turbine (252), wherein the output from turbine is arranged to provide propulsion from rotational movement; a hydrogen source (212) for providing hydrogen to the fuel cell arrangement and the gas generator; an oxygen source (214) for providing oxygen to the gas generator (250), wherein, in use, the gas generator is used selectively to provide electrical energy for additional propulsion.

The present invention relates to a propulsion system for providing controllable propulsion comprising: a fuel cell arrangement (210) for generating electrical energy; a gas generator (250) comprising a compressor (256), a combustor (254) and a turbine (252), wherein the output from turbine is arranged to provide propulsion from rotational movement; a hydrogen source (212) for providing hydrogen to the fuel cell arrangement and the gas generator; an oxygen source (214) for providing oxygen to the gas generator (250), wherein, in use, the gas generator is used selectively to provide electrical energy for additional propulsion.